Move LoopBack4 related repos to new GH org

まだ誰も着手していません。

As [LoopBack joins the OpenJS Foundation](https://openjsf.org/blog/2021/06/02/loopback-joins-openjs-foundation-as-new-incubating-project/), we'll be moving the LoopBack4 related repos to the new GH org: https://github.com/loopbackio

Here are the repos:

1. Core
- [ ] [loopback-next](https://github.com/strongloop/loopback-next)
- [ ] [loopback-datasource-juggler](https://github.com/strongloop/loopback-datasource-juggler) - @marioestradarosa
- [ ] [strong-error-handler](https://github.com/strongloop/strong-error-handler)
- [ ] [explorer.loopback.io](https://github.com/strongloop/explorer.loopback.io)

2. Commonly used connectors and common modules
- [x] [loopback-connector-mysql](https://github.com/strongloop/loopback-connector-mysql)
- [x] [loopback-connector-postgresql](https://github.com/strongloop/loopback-connector-postgresql)
- [ ] [loopback-connector-mongodb](https://github.com/strongloop/loopback-connector-mongodb) - @dhmlau
- [x] [loopback-connector-rest](https://github.com/strongloop/loopback-connector-rest)
- [ ] [loopback-connector-mssql](https://github.com/strongloop/loopback-connector-mssql)
- [ ] [loopback-connector-soap](https://github.com/strongloop/loopback-connector-soap) - @marioestradarosa
- [ ] [loopback-connector-oracle](https://github.com/strongloop/loopback-connector-oracle)
- [x] [loopback-connector-cloudant](https://github.com/strongloop/loopback-connector-cloudant)
- [ ] [loopback-connector-cassandra](https://github.com/strongloop/loopback-connector-cassandra) - @marioestradarosa
- [ ] [loopback-connector-couchdb2](https://github.com/strongloop/loopback-connector-couchdb2) - @marioestradarosa
- [ ] [loopback-connector-db2](https://github.com/strongloop/loopback-connector-db2)
- [ ] [loopback-ibmdb](https://github.com/strongloop/loopback-ibmdb)
- [ ] [loopback-connector-dashdb](https://github.com/strongloop/loopback-connector-dashdb)
- [ ] [loopback-connector-ibmi](https://github.com/strongloop/loopback-connector-ibmi)
- [ ] [loopback-connector-grpc](https://github.com/strongloop/loopback-connector-grpc)
- [ ] [loopback-connector-kv-redis](https://github.com/strongloop/loopback-connector-kv-redis)
- [ ] [loopback-connector-openapi](https://github.com/strongloop/loopback-connector-openapi)
- [ ] [loopback-connector-sqlite3](https://github.com/strongloop-community/loopback-connector-sqlite3) - @marioestradarosa
- [ ] [loopback-connector-elastic-search](https://github.com/strongloop-community/loopback-connector-elastic-search)
- [ ] [loopback-connector-redis](https://github.com/strongloop-community/loopback-connector-redis) - @marioestradarosa
- [ ] [loopback-connector-kv-extreme-scale](https://github.com/strongloop/loopback-connector-kv-extreme-scale)
- [ ] [strong-soap](https://github.com/strongloop/strong-soap) - @marioestradarosa

3. Documentation, examples & extensions

- [ ] [loopback.io](https://github.com/strongloop/loopback.io) - @dhmlau
- [x] [loopback4-example-shopping](https://github.com/strongloop/loopback4-example-shopping)
- [ ] [loopback4-example-kafka](https://github.com/strongloop/loopback4-example-kafka)
- [ ] [loopback4-extension-grpc](https://github.com/strongloop/loopback4-extension-grpc)
- [x] [loopback-governance](https://github.com/strongloop/loopback-governance)

## Acceptance Criteria
For each repo:
- [ ] ~publish a release before moving, if there're changes not in a release yet~ the publish process is smooth after the move, so no need to do this step
- [ ] CI (GitHub Actions and Travis) continues to work
- [ ] uses DCO as contribution method and MIT/Artistic-2.0 license (most repos should be good according to [this](https://gist.github.com/dhmlau/a955bd7b3928df9d79ace0d6b28b5f4c#list-of-all-repos-that-are-part-of-the-project))
- [ ] Code of Conduct (reference: https://github.com/strongloop/loopback-next/blob/master/docs/CODE_OF_CONDUCT.md. Contact email needs to be updated there)

この issue のリポジトリチェックリストと受け入れ基準から始め、次に参照されている docs/CODE_OF_CONDUCT.md パスと、一覧にある各リポジトリの CI および公開設定を確認します。対象となるリポジトリが loopbackio に移行され、CI、コントリビューション方法、ライセンス、Code of Conduct の要件が引き続き提示された基準を満たしていれば完了です。

索引モデルが issue の本文から書いたものです。